Electric fan



BISCHMELZ EIL- ELECTRIC FAN.

APPLICATION FILED MAR. 8, 1921.

. Patnted May 16, 1922.

' INVENTOR BY Zia ATTORNEY breeze which the fan blades are adjusted to am, or messy c, n 2' =1.

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Application filed March 8,

To all whom it may concern Be it known that I, BRUNO SGHMELZER, a citizen of the UnitedStates, and resident of Jersey City, in'the county of Hudson and State of New Jersey, have invented a certain new and useful Electric Fan, of which the following is a specification, the same being a full, clear, and exact description of the invention, such as will enable others skilled in the. art to which it appertains to make and use the same. i

This invention relates to machinesfor creating an artificial current of air by pressure such for example as those in which an armed shaft with wings or beaters revolves in a case and wherein the air may be drawn in bythe revolution of the shaft and attached-fan blades and forcibly discharged at atangential channel or peripheral chute, the air being preferably drawn in at a central opening or openings in the sides of the cats- The invention relates in particular to such fans as are commonly actuated by electric motors and by which a blast of air serves to draw in or to expel a breeze or to keep a circulation of air in the room and whereby, by

the use of my invention, increased 'efliciency, quietness and improved operating characteristics are obtained with a minimum current consumption in proportion to the amount of deliver.

One object of the invention is the provision ofapparatus in which the discharge from the fan is efficiently directed to the desired point, the blast serving to keep the air in agitation.

Another object of the invention is to so design and position the blades or vanes that less power is required to operate them, and to support the same so that they will freely rotate. I preferably employ practically fiat or approximately flat blades which are scoop shaped or cupped and attached to a rotatory shaft. By esignin the parts so that the cutting edge of the lades will as nearly as possible ie in a plane at right angles to the motor shaft undue vibration of the same is obviated and the disagreeable humming sound so common in many fans will be so greatly reduced that the fan will be an almost noiseless one.

We Another object of the invention is to lessen the dip 'or'pitch of the blades so as to reduce the current consumption of the fan as much specification of Letters Patent.

Patented May ilfi, 11922.

1921. Serial No. 450,669.

' as possible without a reduction in the volume of the breeze.

Still another object of the invention is to secure as great a spreadof the breeze as is compatible with a strong blast, and whereby the discharge of air is so operated and of such a nature as to efliciently meet the conditions of practical use.

With the above named and other objects, which will be set forth below, in'view, the invention consists in the construction, arrangement and operation of parts hereinafter described.

In the drawings, illustrative of one embodiment of the invention, which accompany and form a part of this specification,

Figure 1 represents an elevation of an article constructed according to my invention; v

Figure 2 is a partial section on the line 2-2, Figure 1; i

Figure 3 is a view in section taken on the line 3-3, Figure 1 and Figure 4 is an elevation of one of my fan blades and part of the supporting arm therefor.

Upon a sleeve motor shaft, a spider or bracket 2 is mounted to which are attached the shallower inner ends of the blades 3. The arms of the spider are twisted somewhat so that the fan supporting arms will lie at an angle to the 're- .mainder of the bracket in order-to give the 1, which encircles the fan f 4 of the blades is irregularly curved and the said vanes are so arranged that the said outtingedge thereof shall lie in a plane transverse to the motor shaft, the said. cutting edges of all of the vanes traveling in the same path. I

By this arrangement of parts the edges of the blades out through v the vanes striking against the same bodlly, whereby practically the only displacement of the air is that of the thickness of the blades.

the air in lieu of In order to assist in effecting this object,

the body or working face of each blade is dished or cupped, as at 7, so that the portion of the vane adjacent to the cutting edge gradually recedes from the plane in whlch the edges of the blade or vane lie, the line of curvature of the said dished portion decscribin a'cu'rved line at any cross section thereo which conformation of parts assists in afiording practically 'no obstruction of the passage of the forward portion of'the vanes through the air.

The entire body of the blade 1s cup that is to "say it is dished both longitudi nally and transversely by which arrangement the air is gradually drawn in, after which the curvature of the blade forces the air gradually forward until itis finally 1m- .pelled with great power by the rear edge of the cupped vanes which forms the rear boundary edge of a sort of pocket or cavity 7. The said rear edge 5 of theblade is also curved and is also extended rearwardly as at 6, the said rear portion ofQthe blade thus being gradually narrowed, the said edges serving to form a continuous rim.

The reason why my blade is dished is that by the said conformation the air is radually drawn in the blade at the cutting e 'ge thereof and is gradually thrown out and forced forward at and along the entire extent of the cupped rear edge, the rear extension of the said cupped ortion also serving to give a greater spread to the blast of air. llhe dishing of the blade serves to form a rounded pocket in order that insteadof having the air struck by the blade and deflected thereby, it is radually shoved along, as it were, and expelled with great force at the end of the cavity or pocket formed by.

the said cupped rear edge.

By this conformation of partsvthe air is not rarefied or pushed back and forth but a great volume and spread of the blast is obtained. By reason of the shearing action of the cutting edge of my practically flat blade,

only a little resistance is met with and the cupped blade body forces o'r'wedges the air forwardly with a gradually increasing power. w

By reason of the said edges of the cupped body being aligned so\as to lie in the same plane,and of the rear portion ofithe .gradually deepening pocket terminating at the rear edge of the vane, a'full volume of the blast is-forc ibly impelled forwardly with great force with the maximum desirable spread, inasmuch as the. air is not discharged from the rear edge of the blades alone, but

is shed alongthe entire extent of the length of the'rear edge of the same thus providlng a full and solid column of air. I

By practically ali ning the cutting edge of each, vane, said b ades arenot subjected to back pressure or undue strain. The blades are preferably made. of rigid sheet brass and the edges of the same are neither bent longitudinally or transversely butthe blades are of practically flat conformation cupped, and are of sufficient stifi'nes to resist torsional strain in case any should develop, and they serve in operation to throw large volumes of air with little or no noise, other than the-sound produced by the rushlng air,ra nd with a minimum consumption of release current. The advantagesof a solid column V of air formed by the discharge from the entire length of the blade over a cylindrical hollow column of air which results where the air is impelled merely by the ends of the vanes, are manifest.

I wish it to be understood that I do not.

desire to be limited to the particular use or the exact-details of-construction shown and described, for obvious modifications will occur to persons skilled inthe art.

\ Vhat I claim as my invention is 1. In a deviceof the class described, a

blade having a curved cutting edge constructed and arranged to cut the air in a plane at an angle to the axis of rotation and a curved rear edge, the body or working plane at an angle to the axis of rotation and a curved rear edge, the body or face of the blade being dished in such a manner that the airis forced out and thrown forward along the entire dished rear edge, all of the edges "of the blade lying in the same plane.

3. In a device of the class described," a

blade having a curvedcutting edge con-' structed and arranged to cut the air in a plane at an angle to the axis of rotation and a rear edge having a rearward extension,

the body or working face of the blade being dished so as to be deepest at the central part thereof and so formed that the air is forced out and thrown forward along the entire dished rear edge, all of the edges of the blade lying in the ame plane.

4. In a device of the class described, a blade having a curved cfitting edge constructed and arranged to cut the air at an angle to the axis of rotation and a dished body comprising a cavity formed in the body or working face of the blade extending to and along the entire cutting edge and also. i e

extending to the entire curved rear edg'eto form a rim, the said cavit growing shallower as it approaches the mner end of the.

5,111 a device of the class described, a blade having a curved cuttin edge to cut the air at an angle tothe axis of rotation,

and a cavity formed by dishing the body or workingface of the blade extending to and along the entire cutting edge and also extendingto the entire curvedrear edge and also to the entire rearward narrower exten sion thereof to form a continuous rimalong all of the said edges, by whichthe air is v forced out and thrown forward at along the entire dished/rear edge, the rear extension srving to givegreater spread to the blast 0 am 6. In a device of the class described, a bladehaving a curved cutting edge and a dished body comprising a cavity formed in the body or Working face of the blade commencing at the shallower inner end of the blade and extending to the entire cutting edge,'the blade also having a curved rear edge, the said cavity also extending to the entire rear edge, the line of curvature of the said dished portion describing a curved lineat any cross section thereof. v

7. In a device of the class described, a blade having a curved cutting edge and a dished body comprising a cavity formed in the body or Working face of the blade commencing at the said cutting edge, the blade also having a curved rear edge, the said cavity meeting the said rear edge, the line of curvature of the edge of the said dishedortion descrlbing' a curved line at any cross section thereof, all of the edges of thebladc lying in one plane.

8. In a device of the class described, a

blade having a body portion and curved cut- 1 ting and rear edges, the said body being dished both longitudinally and transversely,

the line of curvature of the edges of the said dished portion describing a curved line at any cross section thereon, all of the edges of the blade lying in one plane.

Signed at New York, in the county of New York and State of New York, this 1st day of March, A. D. 1921. l

, BRUNO SCHMELZER. 

